Heat source machine

ABSTRACT

A heat source machine includes: a first emission amount calculation unit  12  which calculates a first carbon dioxide emission amount that is an amount of carbon dioxide emitted to obtain an energy source consumed in a hot-water supply operation; a second emission amount calculation unit  13  which calculates a second carbon dioxide emission amount that is an amount of carbon dioxide emitted to obtain an energy source consumed in a reference heat source machine on an assumption that the reference heat source machine performs the same operation as the hot-water supply operation; and a carbon dioxide emission reduction degree display unit  14  which displays a carbon dioxide emission reduction degree that results from changing to the current heat source machine, according to a difference between the first carbon dioxide emission amount and the second carbon dioxide emission amount.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a heat source machine having a function of displaying a carbon dioxide emission reduction degree.

2. Description of the Related Art

As a conventional heat source machine, there is proposed a latent heat recovery-type hot-water supply device which calculates a carbon dioxide emission reduction amount with respect to a reference hot-water supply device (a standard hot-water supply device), and displays information of the carbon dioxide emission reduction amount on a display screen of a remote control (for example, see Japanese Patent Application Laid-Open No. 2004-20150).

The hot-water supply device described in the above-mentioned patent document allows a user to recognize to what degree carbon dioxide emissions are reduced with respect to the reference hot-water supply device as a result of replacing with the latent heat recovery-type hot-water supply device.

In the case where the user replaces a previously used heat source machine with a heat source machine of higher thermal efficiency, the user is likely to be interested to know to what degree carbon dioxide emissions are reduced as a result of the replacement of the heat source machine. However, the above-mentioned conventional heat source machine merely displays the information of the carbon dioxide emission reduction amount in comparison with the uniform reference heat source machine, and so cannot meet the user's interest.

In view of this, the present invention has an object of providing a heat source machine capable of displaying a carbon dioxide emission reduction degree with respect to a previously used heat source machine.

SUMMARY OF THE INVENTION

The present invention has been made to achieve the stated object, and relates to a heat source machine which performs a heating operation of heating water to be heated by a heating unit.

The heat source machine includes: a comparison target input unit which inputs specifications of a reference heat source machine as a comparison target; a first emission amount calculation unit which calculates a first carbon dioxide emission amount, the first carbon dioxide emission amount being an amount of carbon dioxide emitted to obtain energy consumed in the case of performing the heating operation; a second emission amount calculation unit which calculates a second carbon dioxide emission amount, the second carbon dioxide emission amount being an assumed amount of carbon dioxide emitted to obtain energy consumed in the reference heat source machine on an assumption that the reference heat source machine performs the same operation as the heating operation; and a carbon dioxide emission reduction degree display unit which displays a carbon dioxide emission reduction degree that results from changing to the heat source machine, according to a difference between the first carbon dioxide emission amount and the second carbon dioxide emission amount (first invention).

According to the first invention, a user who replaces a previously used heat source machine or a user who changes his/her residence and as a result uses a heat source machine different from the previously used heat source machine can input specifications of the previously used heat source machine by the comparison target input unit. The carbon dioxide emission reduction degree display unit displays the carbon dioxide emission reduction degree that results from changing to the current heat source machine, with respect to the heat source machine of the specifications input by the comparison target input unit as the reference heat source machine. Hence, when the user uses a heat source machine of higher thermal efficiency than the previously used heat source machine, the user can recognize, by viewing the display, the carbon dioxide emission reduction degree that results from changing to the current heat source machine.

Note that energy consumed in the case of performing the heating operation is thermal energy generated by burning fuel with a burner in the case where the heat source machine is a gas heat source machine or an oil heat source machine, and thermal energy converted from electric power in the case where the heat source machine is an electric heat source machine such as an electric water heater. Carbon dioxide emitted to obtain energy consumed in the case of performing the heating operation is carbon dioxide emitted when burning fuel with a burner in the case where the heat source machine is a gas heat source machine or an oil heat source machine, and carbon dioxide emitted when generating electric power (such as thermal power generation) in the case where the heat source machine is an electric heat source machine.

The carbon dioxide emission reduction degree displayed by the carbon dioxide emission reduction degree display unit includes a reduction amount (absolute quantity) and a reduction proportion (relative quantity) of carbon dioxide emissions with respect to the reference heat source machine.

Moreover, the comparison target input unit is capable of inputting, as the specifications of the reference heat source machine as the comparison target, at least one of an electric water heater, an oil heat source machine, a gas heat source machine using natural gas, and a gas heat source machine using liquefied petroleum gas (second invention).

According to the second invention, the carbon dioxide emission reduction degree display unit can display the carbon dioxide emission reduction degree with respect to the reference heat source machine that is any of an electric water heater, an oil hot-water supply device, a natural gas hot-water supply device, and an LPG (liquefied petroleum gas) hot-water supply device which are typically used as heat source machines.

Moreover, the heating unit includes: a burner; a main heat exchanger which mainly absorbs sensible heat from exhaust gas of the burner and performs heat transfer; and an auxiliary heat exchanger which mainly absorbs latent heat from the exhaust gas of the burner and performs heat transfer, and the comparison target input unit is capable of inputting, as the specifications of the reference heat source machine as the comparison target, a hot-water supply device including only a burner and a heat exchanger which mainly absorbs sensible heat from exhaust gas of the burner and performs heat transfer (third invention).

According to the third invention, a heat source machine including only a heat exchanger which mainly absorbs sensible heat and performs heat transfer can be input as the reference heat source machine. The carbon dioxide emission reduction degree display unit can then display the carbon dioxide emission reduction degree that results from replacement with a latent heat recovery-type heat source machine including a main heat exchanger which mainly absorbs sensible heat and performs heat transfer and an auxiliary heat exchanger which mainly absorbs latent heat and performs heat transfer.

Moreover, the heating unit includes: a first heating unit which performs a hot-water supply operation of supplying hot water to a hot-water supply pipe, as the heating operation; and a second heating unit which performs a room heating operation of supplying hot water to a room heating circuit, as the heating operation, the first emission amount calculation unit separately calculates the first carbon dioxide emission amount in the case of performing the hot-water supply operation and the first carbon dioxide emission amount in the case of performing the room heating operation, the second emission amount calculation unit separately calculates the second carbon dioxide emission amount in the case of performing the hot-water supply operation and the second carbon dioxide emission amount in the case of performing the room heating operation, and the carbon dioxide emission reduction degree display unit separately calculates and displays the carbon dioxide emission reduction degree that results from changing to the heat source machine in the case of performing the hot-water supply operation and the carbon dioxide emission reduction degree that results from changing to the heat source machine in the case of performing the room heating operation (fourth invention).

According to the fourth invention, in a composite heat source machine which performs a hot-water supply operation and a room heating operation, the carbon dioxide emission reduction degree that results from changing to the current heat source machine in the case of performing the hot-water supply operation and the carbon dioxide emission reduction degree that results from changing to the current heat source machine in the case of performing the room heating operation can be separately recognized by the user.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram showing a structure of a heat source machine.

FIG. 2 is a diagram showing a comparison target selection screen.

FIG. 3 is a flowchart of a process of displaying a carbon dioxide emission reduction degree.

FIG. 4 is a diagram showing a CO₂ reduction degree display screen 1.

FIG. 5 is a diagram showing a CO₂ reduction degree display screen 2.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following describes an embodiment of the present invention with reference to FIGS. 1 to 5.

In FIG. 1, a gas heat source machine 1 of this embodiment (corresponding to a heat source machine according to the present invention) is a high-efficiency, latent heat recovery-type heat source machine having a hot-water supply function and a room heating function, and uses natural gas as fuel gas.

The gas heat source machine 1 includes: a hot-water supply main heat exchanger 100 a (mainly absorbing sensible heat from exhaust gas of a hot-water supply burner 101) and a hot-water supply auxiliary heat exchanger 100 b (mainly absorbing latent heat from the exhaust gas of the hot-water supply burner 101) that are provided at some intermediate point of a hot-water supply pipe 105 and heat water to be heated flowing through the hot-water supply pipe 105; and a room heating main heat exchanger 110 a (mainly absorbing sensible heat from exhaust gas of a room heating burner 111) and a room heating auxiliary heat exchanger 110 b (mainly absorbing latent heat from the exhaust gas of the room heating burner 111) that are provided at some intermediate point of a room heating circuit 115 and heat water to be heated flowing through the room heating circuit 115.

The hot-water supply burner 101 is made up of a large burner 101 a, a medium burner 101 b, and a small burner 101 c, whereas the room heating burner 111 is made up of a large burner 111 a and a small burner 111 b.

Note that the hot-water supply main heat exchanger 100 a, the hot-water supply auxiliary heat exchanger 100 b, and the hot-water supply burner 101 constitute a first heating unit according to the present invention, and the room heating main heat exchanger 110 a, the room heating auxiliary heat exchanger 110 b, and the room heating burner 111 constitute a second heating unit according to the present invention.

The gas heat source machine 1 includes: a hot-water supply gas solenoid valve 71 which switches on and off of fuel gas supply to the large burner 101 a; a hot-water supply gas solenoid valve 72 which switches on and off of fuel gas supply to the medium burner 101 b; a hot-water supply gas solenoid valve 73 which switches on and off of fuel gas supply to the small burner 101 c; a room heating gas solenoid valve 74 which switches on and off of fuel gas supply to the large burner 111 a; a room heating gas solenoid valve 75 which switches on and off of fuel gas supply to the small burner 111 b; a main gas solenoid valve 70 which switches on and off of fuel gas supply to the hot-water supply burner 101 and the room heating burner 111; a gas proportional valve 121 which adjusts a fuel gas supply flow rate to the hot-water supply burner 101 and the room heating burner 111; and a fan 130 which supplies combustion air to the hot-water supply burner 101 and the room heating burner 111.

The gas heat source machine 1 further includes a controller 10 which controls the main gas solenoid valve 70, the gas proportional valve 121, the hot-water supply gas solenoid valves 71, 72, and 73, the room heating gas solenoid valves 74 and 75, and the fan 130, to perform a hot-water supply operation while controlling a temperature of hot water discharged in the hot-water supply pipe 105 and a room heating operation while controlling a temperature of hot water discharged in the room heating circuit 115.

The controller 10 is an electronic unit composed of a CPU, a memory, and the like not shown. The CPU executes a control program of the gas heat source machine 1, thereby functioning as a comparison target input unit 11, a first emission amount calculation unit 12, a second emission amount calculation unit 13, and a carbon dioxide emission reduction degree display unit 14. A remote control 20 for remotely controlling the gas heat source machine 1 is connected to the controller 10.

The comparison target input unit 11, the first emission amount calculation unit 12, the second emission amount calculation unit 13, and the carbon dioxide emission reduction degree display unit 14 are configured to enable a user of the gas heat source machine 1 to display, on a display 30 of the remote control 20, a carbon dioxide emission reduction degree that results from changing to the gas heat source machine 1, with respect to another heat source machine used previously.

In FIG. 2, when the user operates a mode selector switch 21 of the remote control 20 to select “comparison target input mode”, the comparison target input unit 11 displays a comparison target selection screen 50 prompting to select the previously used heat source machine, on the display 30 of the remote control 20.

The user operates an up switch 22 or a down switch 23, to select specifications of the previously used heat source machine (any one of 1: conventional gas heat source machine (natural gas), 2: conventional gas heat source machine (LPG), 3: oil heat source machine, and 4: electric water heater) on the comparison target selection screen 50.

FIG. 2 shows a state where the oil heat source machine is selected. Note that the conventional gas heat source machine is a gas heat source machine that includes only a heat exchanger for sensible heat recovery and does not include a heat exchanger for latent heat recovery.

The heat source machine as the comparison target (reference heat source machine) is determined by the user operating a set switch 24. Note that, in a heating operation of a heat source machine, thermal energy generated by burning natural gas, LPG (liquefied petroleum gas), or oil with a burner or thermal energy converted from electric power corresponds to energy consumed in the case of performing a heating operation according to the present invention.

The following describes processes performed by the first emission amount calculation unit 12, the second emission amount calculation unit 13, and the carbon dioxide emission reduction degree display unit 14 when the gas heat source machine 1 performs the hot-water supply operation, with reference to a flowchart shown in FIG. 3.

STEPS 1 to 3 constitute a process performed by the first emission amount calculation unit 12. In STEP 1, the first emission amount calculation unit 12 integrates a consumption amount (output amount) of fuel gas (natural gas) calculated using a water supply temperature, a preset temperature, and a water supply flow amount in the hot-water supply operation of the gas heat source machine 1 (current gas heat source machine), on a day-to-day basis.

In next STEP 2, the first emission amount calculation unit 12 divides an integrated fuel gas amount Gc calculated in STEP 1 by an efficiency conversion value μ11 given in Table 1 shown below, to calculate an integrated energy amount (input amount) Se used in the hot-water supply operation (corresponding to energy consumed in the case of performing the heating operation according to the present invention).

In next STEP 3, the first emission amount calculation unit 12 calculates Ex1 (first carbon dioxide emission amount) which is an amount of carbon dioxide emitted with burning of natural gas for obtaining the integrated energy amount Se, according to the following Equation (1).

Ext1=Se*K1  (1)

where K1 is a CO₂ unit conversion value according to Table 1 shown below. Since the gas heat source machine 1 uses natural gas, K1=0.0506.

TABLE 1 Efficiency CO₂ unit conversion Efficiency Currently used conversion value μ11 conversion heat source Energy value K1 (hot-water value μ12 machine source (kgCO₂/MJ) supply) (room heating) 1 High-efficiency 13A 0.0506 0.95 0.87 heat source (natural machine gas) 2 High-efficiency LPG 0.0598 0.95 0.87 heat source machine

Next STEP 4 constitutes a process performed by the second emission amount calculation unit 13. The second emission amount calculation unit 13 calculates Ex2 (second carbon dioxide emission amount) which is an assumed amount of carbon dioxide emitted with burning of oil on an assumption that the oil heat source machine as the comparison target (reference heat source machine) performs the same hot-water supply operation as the gas heat source machine 1, according to the following Equation (2).

Ex2=Ex1*(μ11/μ21)*(K2/K1)  (2)

where Ex1 is the amount of carbon dioxide emitted with burning of natural gas for obtaining the integrated energy amount Se, μ11 is the efficiency conversion value in the hot-water supply operation of the gas heat source machine 1 (=0.95), μ21 is an efficiency conversion value in the hot-water supply operation of the oil heat source machine (=0.84) according to Table 2 shown below, K1 is the CO₂ unit conversion value of the gas heat source machine 1 (=0.0506), and K2 is a CO₂ unit conversion value of the oil heat source machine (=0.0678) according to Table 2 shown below.

TABLE 2 Previously used Efficiency Efficiency heat source CO₂ unit conversion conversion machine conversion value μ21 value μ22 (reference heat Energy value K2 (hot-water (room source machine) source (kgCO₂/MJ) supply) heating) 1 Conventional 13A 0.0506 0.84 0.81 gas heat source (natural machine gas) 2 Conventional LPG 0.0598 0.84 0.81 gas heat source machine 3 Electric water Electricity 0.1917 0.85 1 heater 4 Oil heat source Kerosene 0.0678 0.84 0.8 machine

Note that the data of Tables 1 and 2 shown above are held in a memory beforehand.

Next STEPS 5 to 7 constitute a process performed by the carbon dioxide emission reduction degree display unit 14. In STEP 5, the carbon dioxide emission reduction degree display unit 14 calculates a difference ΔEx between the first carbon dioxide emission amount Ext1 calculated by the first emission amount calculation unit 12 and the second carbon dioxide emission amount Ex2 calculated by the second emission amount calculation unit 13, as a carbon dioxide emission reduction amount of the gas heat source machine 1 (current heat source machine) with respect to the oil heat source machine (previously used heat source machine, i.e., reference heat source machine).

In next STEPS 6 and 7, the carbon dioxide emission reduction degree display unit 14 displays a CO₂ reduction degree display screen 60 on the display 30 of the remote control 20, as shown in FIG. 4. In the CO₂ reduction degree display screen 60, a carbon dioxide emission reduction amount of the day and a cumulative carbon dioxide emission reduction amount from beginning of use are displayed in a CO₂ reduction amount display portion 61, and also a value 62 indicating the number of cedar trees equivalent to the cumulative carbon dioxide emission reduction amount and graphics 63 indicating a cedar tree size equivalent to the cumulative carbon dioxide emission reduction amount are displayed.

Moreover, when the cumulative carbon dioxide emission reduction amount reaches a predetermined amount or more, the carbon dioxide emission reduction degree display unit 14 displays, on the display 30 of the remote control 20, a CO₂ reduction degree display screen 65 that includes a value 66 indicating the number of forests of cedar trees equivalent to the reduction amount and graphics 67 of a forest image, as shown in FIG. 5.

As shown in FIGS. 4 and 5, by displaying the carbon dioxide emission reduction degree on the display 30 of the remote control 20, the user who has replaced the conventional oil heat source machine with the high-efficiency latent heat recovery-type gas heat source machine 1 can be satisfied that the replacement contributes to protection of natural environment.

The case where the gas heat source machine 1 performs the hot-water supply operation is described in the flowchart of FIG. 3. However, even in the case where the gas heat source machine 1 performs the room heating operation, the carbon dioxide emission reduction amount that results from the replacement with the gas heat source machine 1 can equally be calculated and displayed on the display 30 of the remote control 20 through the use of the efficiency conversion value μ12 for the room heating operation in Table 1 shown above and the efficiency conversion value μ22 for the room heating operation in Table 2 shown above.

This embodiment describes an example where the oil heat source machine is selected as the previously used heat source machine. However, even in the case where the conventional (not the latent heat recovery type) gas hot-water supply device (natural gas or LPG) or the electric water heater is selected, the carbon dioxide emission reduction amount can equally be calculated and displayed on the display 30 of the remote control 20 through the use of the corresponding CO₂ unit conversion value K2 and the efficiency conversion value μ21 or μ22 in Table 2 shown above.

This embodiment describes an example where the heat source machine as the comparison target is selected from the conventional (not the latent heat recovery type) gas heat source machine (natural gas or LPG), the oil heat source machine, and the electric water heater. However, all of these devices need not necessarily be presented as options. Alternatively, the user may input a type name of the heat source machine as the comparison target. The user may further input a type year of the heat source machine as the comparison target so that the setting of the efficiency conversion value is changed according to the type year.

This embodiment describes the latent heat recovery-type natural gas heat source machine 1 including the main heat exchangers 100 a and 110 a and the auxiliary heat exchangers 100 b and 110 b, as the heat source machine according to the present invention. However, the present invention is also applicable to heat source machines of other types.

This embodiment describes the composite gas heat source machine 1 which performs the hot-water supply operation and the room heating operation, as the heat source machine according to the present invention. However, the present invention is also applicable to a heat source machine specifically designed for hot-water supply and a heat source machine specifically designed for room heating.

This embodiment describes the case where the carbon dioxide emission reduction degree display unit 14 displays the carbon dioxide emission reduction degree with respect to the reference heat source machine as a reduction amount (absolute value), in the CO₂ reduction degree display screens 60 and 65. However, the carbon dioxide emission reduction degree with respect to the reference heat source machine may instead be displayed as a reduction proportion (relative value). For example, the reduction proportion may be calculated using Ext1 in the above-mentioned Equation (1) and Ex2 in the above-mentioned Equation (2), according to the following Equation (3).

Reduction proportion=(Ex2−Ex1)/Ex2*100(%)  (3) 

1. A heat source machine which performs a heating operation of heating water to be heated by a heating unit, the heat source machine comprising: a comparison target input unit which inputs specifications of a reference heat source machine as a comparison target; a first emission amount calculation unit which calculates a first carbon dioxide emission amount, the first carbon dioxide emission amount being an amount of carbon dioxide emitted to obtain energy consumed in the case of performing the heating operation; a second emission amount calculation unit which calculates a second carbon dioxide emission amount, the second carbon dioxide emission amount being an assumed amount of carbon dioxide emitted to obtain energy consumed in the reference heat source machine on an assumption that the reference heat source machine performs the same operation as the heating operation; and a carbon dioxide emission reduction degree display unit which displays a carbon dioxide emission reduction degree that results from changing to the heat source machine, according to a difference between the first carbon dioxide emission amount and the second carbon dioxide emission amount.
 2. The heat source machine according to claim 1, wherein the comparison target input unit is capable of inputting, as the specifications of the reference heat source machine as the comparison target, at least one of an electric water heater, an oil heat source machine, a gas heat source machine using natural gas, and a gas heat source machine using liquefied petroleum gas.
 3. The heat source machine according to claim 1, wherein the heating unit includes: a burner; a main heat exchanger which mainly absorbs sensible heat from exhaust gas of the burner and performs heat transfer; and an auxiliary heat exchanger which mainly absorbs latent heat from the exhaust gas of the burner and performs heat transfer, and wherein the comparison target input unit is capable of inputting, as the specifications of the reference heat source machine as the comparison target, a heat source machine including only a burner and a heat exchanger which mainly absorbs sensible heat from exhaust gas of the burner and performs heat transfer.
 4. The heat source machine according to claim 1, wherein the heating unit includes: a first heating unit which performs a hot-water supply operation of supplying hot water to a hot-water supply pipe, as the heating operation; and a second heating unit which performs a room heating operation of supplying hot water to a room heating circuit, as the heating operation, wherein the first emission amount calculation unit separately calculates the first carbon dioxide emission amount in the case of performing the hot-water supply operation and the first carbon dioxide emission amount in the case of performing the room heating operation, wherein the second emission amount calculation unit separately calculates the second carbon dioxide emission amount in the case of performing the hot-water supply operation and the second carbon dioxide emission amount in the case of performing the room heating operation, and wherein the carbon dioxide emission reduction degree display unit separately calculates and displays the carbon dioxide emission reduction degree that results from changing to the heat source machine in the case of performing the hot-water supply operation and the carbon dioxide emission reduction degree that results from changing to the heat source machine in the case of performing the room heating operation. 